Study "biology", a flashcard deck on FORKSAI.
THEORETICAL: Explain how the structure of carbohydrates differs from that of lipids, in terms of their basic building blocks.
Carbohydrates are large molecules made up of smaller glucose units. Lipids, on the other hand, are composed of glycerol and fatty acids. While both contain carbon, hydrogen, and oxygen, their elemental arrangement and subunit structures are distinct.
MCQ-STYLE: Which of the following is NOT a primary function of food for the human body? A) To supply fuel for energy B) To provide materials for growth and repair C) To produce oxygen for respiration D) To help fight disease and keep bodies healthy
C) To produce oxygen for respiration. Food provides energy, materials for growth and repair, and helps fight disease, but the body obtains oxygen for respiration from the air, not directly from food.
DEFINITION: Define what a 'balanced diet' means in the context of human nutrition.
A balanced diet is one that provides enough of each group of nutrients in the correct amounts and proportions. It ensures the body receives all necessary components for energy, growth, repair, and overall health.
APPLICATION/PRACTICAL: A person is experiencing symptoms of fatigue and weakness. A doctor suspects a dietary deficiency. If the person's diet is lacking in red meat and green vegetables, which mineral deficiency is most likely causing these symptoms, and why?
The person is most likely suffering from an iron deficiency, leading to anaemia. Iron is a crucial component of haemoglobin in red blood cells, which is responsible for transporting oxygen. A lack of iron impairs oxygen transport, resulting in tiredness and weakness.
THEORETICAL: Describe the role of cellulose in the human diet, considering that humans cannot digest it.
Although humans cannot digest cellulose, it is an essential component of the diet known as dietary fibre. It plays a crucial role in preventing constipation and serious diseases by adding bulk to stool and aiding in the smooth movement of food through the gut.
DEFINITION: Distinguish between sugars and starch in terms of their solubility and general structure.
Sugars are typically soluble and taste sweet, often found as smaller glucose molecules. Starch, however, is insoluble and a large polymer of glucose, meaning it's a complex carbohydrate made of many glucose units linked together.
MCQ-STYLE: Which of the following is a primary function of lipids in the human body? A) Building new cells for growth B) Acting as a storage carbohydrate in plants C) Providing insulation under the skin D) Transporting oxygen in red blood cells
C) Providing insulation under the skin. Lipids serve as an energy store, make cell membranes, and provide insulation and organ protection. Building new cells is primarily a protein function, starch is a plant carbohydrate, and oxygen transport is via iron in haemoglobin.
EXPERIMENTAL: Imagine you are investigating food samples for the presence of different nutrients. What specific substances would you be looking for to confirm the presence of carbohydrates, proteins, and fats?
To confirm carbohydrates, you would test for glucose (a simple sugar) and starch. For proteins, you would look for the presence of amino acids. For fats (lipids), you would be looking for the presence of glycerol and fatty acids.
APPLICATION/PRACTICAL: A child in a developing country exhibits symptoms including a swollen belly and stunted growth. Based on the provided notes, what dietary deficiency is most likely responsible for these symptoms, and what is the name of the associated condition?
These symptoms are characteristic of a protein-deficiency disease called kwashiorkor. Proteins are essential for building new cells for growth and repair, and a severe lack of them, common in poor countries, leads to impaired development and other health issues.
THEORETICAL: Explain why carbohydrates need to be digested into sugars before they can be absorbed into the blood.
Carbohydrates, especially complex ones like starch, are large, insoluble molecules. They must be broken down into smaller, soluble sugar units (like glucose) by digestive enzymes to pass through the intestinal lining and be absorbed into the bloodstream for transport to cells.